Head set construction

ABSTRACT

Headset construction including headband and earcups having connecting means therebetween allowing smooth dampened swivelling action of earcups into desired close-fitting positions against wearer&#39;&#39;s head and about his ears and with said connecting means arranged to allow headband to be readily adjusted to different lengths and pivoted relative to earcups so as to be worn in any one of several different positions as conditions of use require.

United States Patent [191 Beguin 1March 13, 1973 [73] Assignee: AmericanOptical Corporation, Southbridge, Mass.

22 Filed: Feb. 12,1970 21 Appl.N0.: l0,787

[52] US. Cl ..2/209 [51] Int. Cl. ..A41d 21/00 [58] Field of Search..2/209, 3, 6, 8, 174; 179/182 R, 156; 248/256 [56] References CitedUNITED STATES PATENTS 2,858,544 11/1958 Roth ..2/209 2,506,981 4/1970Stewart et a1 ..2/209 2,505,684 4/1970 Hutchinson et a1. ..2/2093,108,282 10/1963 Rehman et al ..2/209 X 3,461,463 8/1969 Beguin ..2/209X 2,437,748 3/1948 Malcom ..2/8

FOREIGN PATENTS OR APPLICATIONS 1,145,964 5/1957 France ..2/209 PrimaryExaminerGeorge H. Krizmanieh Attorney-William C. Nealon, Noble S.Williams and Robert J. Bird [57] ABSTRACT Headset construction includingheadband and earcups having connecting means therebetween allowingsmooth dampened swivelling action of earcups into desired close-fittingpositions against wearer's head and about his ears and with saidconnecting means arranged to allow headband to be readily adjusted todifferent lengths and pivoted relative to earcups so as to be worn inany one of several different positions as conditions of use require,

2 Claims, 7 Drawing Figures PATH-HEUMAR 1 31973 sum 2 or 2 INVENTOR.FRED P BEGUIN FIG? I AT ORNEY HEAD SET CONSTRUCTION This inventionrelates to improvements in headset constructions for ambient soundattenuation, and more particularly to a headset construction comprisinga headband and a pair of earcups having improved connecting meanstherebetween for allowing each earcup to be smoothly universallyswivelled into any desired position of use against the wearers head andin closefitting relation about the wearers ears while also allowing theheadband to be adjusted in length, as required, and moved into andretained in any one of several different operative positions during useof the headset.

More particularly, the headset comprises a flexible headband and a pairof earcups which are swivelly carried upon opposite end portions of theflexible headband by improved connecting means which is of suchconstruction and arrangement as to provide smooth firm frictionalsliding resistance to the movable parts of the structure as well asallow the wearer of the headset to easily and readily adjust each earcupinto its proper position surrounding the wearers ear and bearing inclose-fitting condition against the wearers head. At the same time, theconnecting means construction and arrangement is such that the flexibleheadband may be readily adjusted as needed without requiring thetightening or loosening of parts, to position the headband over thehead, or under the chin, or even in back of the head near the wearersneck as desired. Furthermore, the built-in frictional resistance of theadjustable parts of the structure is such that it will thereafter tendto retain the headband in such adjusted position unless forcefullydisturbed or purposely manipulated; and this built-in frictionalresistance will remain substantially constant even though the parts arepivoted many hundreds of times during the use thereof.

The improved connecting means mentioned above between each earcup and anend portion of the headband and providing the so-called built-infrictional resistance includes ball-and-socket means which has been socarefully controlled during the production thereof as to size of partsand physical characteristics of materials employed that not only willsmooth sliding action of the parts be had over long periods of use butalso it will be such that the amount of frictional resistance desiredwill be provided and will be maintained substantially constant. Thus,the smooth firm dampened sliding condition between the parts will alwaysbe present and this frictional resistance can always be depended upon tohold the parts in their adjusted posi tion during use of the device.Also, the controlled character and arrangement of the parts and thesmooth firm frictional resistance provided is such that the headband maybe easily adjusted lengthwise for different conditions requiringdifferent distances between the earcups carried near the opposite endsthereof. Additionally, the improved construction comprises adjustableslidable connecting means which is such that said headset may be readilyadapted to fit any one of a wide range of different size requirementsfor different conditions of use.

It is, accordingly, an object of the present invention to provide animproved headset comprising a flexible headband and a pair of earcupscarried near the opposite ends of said headband by connecting meanswhich is of such improved construction and arrangement that each earcupmay be universally swivelled suitable amounts in any direction withreference to said headband in order to allow the earcup to fit about thewearers ears and evenly and snugly against the wearers head, and whichearcups may each be rotated as desired about its central axis forfitting purposes. Also, the connecting means allows the headband to bepivoted as desired into any one of its several normal operativepositions above, in front of or to the rear of the wearers head andfirmly frictionally retained in any such operative position during usethereof. It is also an object of the present invention to provide amethod for making ball-and-socket connections of the character describedand which are such as may be used between the headband and earcups of asound-attenuating headset, a stereo headset, a communication headset orthe like, the connections allowing limited universal swivelling smoothlydamped movement of the earcups of the like relative to its supportingstructure, such as the headband while providing proper amounts offriction resistance between the operative parts thereof such that notonly can the desired adjustments of the earcups to a wearers head beeasily and smoothly made but also, at the same time, sufficient amountsof resistance to change of position are provided. Thus, the headband andearcups will normally be retained in their adjusted positions duringnormal use of the equipment and, on the other hand, the earcups may bereadily forcefully pressed, without the loosening or tightening of anyparts, into any other position of adjustment desired.

Other objects and advantages of the invention will be apparent from thedetailed description which follows when taken in conjunction with theaccompanying drawings wherein:

FIG. 1 is a perspective view of a headset embodying the presentinvention;

FIG. 2 is an enlarged fragmentary view of a part of the structure ofFIG. 1;

FIG. 3 is a transverse sectional view taken substantially upon sectionline 3-3 of FIG. 2 and looking in the direction of the arrows;

FIG. 4 is an exploded view of the parts of the structure of FIG. 3;

FIG. 5 is a fragmentary side elevational view showing a modified form ofthe invention; 7

FIG. 6 is a vertical sectional view taken substantially along sectionline 6-6 of FIG. 5; and

FIG. 7 is a vertical sectional view showing complementary mold parts foruse in carrying out method steps of the present invention.

Referring to the drawings in detail and in particular FIG. 1, there isindicated at 10 a headset comprising a resilient or spring-type headbandl2 and a pair of earcups 14 carried thereby. The connecting means forthis purpose will be later described. Preferably, the headband would beformed of flat spring steel, stiff plastic, fiber glass or the like ofsuch characteristics as to afford the firm but yieldable pressuredesired between the earcups and the opposite sides of the wearer's headwhile in use.

Each earcup is of a hollow one-piece construction and formed of amoldable plastic material. As shown, the earcup comprises an outergenerally circular wall portion 14a peripherally connected to an endlessside portion 14b of frusto-conical shape. The molded earcup is open atits inner side but may be provided with a small endless flange at itsinner edge arranged to receive andhelp retain the outer thin flange of aflexible head-engaging resilient ear pad or cushion 16 in overlappingengagement with this peripheral flange. The cushion is providedcentrally therein with an elongated opening 18 of suitable size andshape for receiving the ear of the wearer therein. A pair of front andrear flattened portions 20 are formed upon the outer surface of the wallportion 14b of each earcup in order to enable the wearer to easily feeland determine thereby the position of the earcup opening 18 withouthaving to remove the headset.

Carried in the outer wall portion 14a of each earcup is a ball-headedstud 22 formed of metal, (see also FIGS. 2 and 3) which has its polishedsphericallyshaped head portion 22a embedded within he plastic of theearcup during the molding thereof. In this way, the head portion 22a ispermanently contained within and firmly gripped by the plastic forming asocket 25 in the molded plastic materialof the outer wall portion 14b atan enlarged thickened central region 24 thereof. The moldedplastic-material about the stem portion 22b of the stud 22 is recessedat 27 in such a manner that limited universal pivotal movement of thestud about the geometric center of the ball-headed part 22a and relativeto the earcup may be accomplished. The allowable pivotal movement of thestud in any direction from its centered position would be, in mostcases, an angular amount approximating 15 to 20.

The stem portion 22b of the ball-headed stud 22, as shown in FIG. 3, isarranged to extend outwardly through an elongated slot 38 formed in anend portion 12a of the headband 12 and through a pair of frictionwashers 30 and 32, preferably formed of a plastic, like nylon or teflon,disposed at opposite sides of the slotted end portion 12a. (Note thatthe construction and arrangement of parts for supporting the earcups ofa headset are identical.) The outer end 22a of the stud of FIG. 3 isthreaded to receive an adjustable stop-nut 34 and a spring washer islocated between this nut and outer friction washer 32. This nut 34 canbe easily adjusted to exert the amount of clamping action needed betweenthe friction washers 30, 32 and the slotted end portion to preventunwanted longitudinal sliding action therebetween.

In order to prevent rotation between inner washer 30 and stud 22, asmall pin 42 is provided (see FIG. 4) and arranged to extend through abore 44 in the stud in such a way as to have engagement with a groove 46provided in an upstanding collar portion 48 of inner washer 30. At thesame time, in order to prevent rotation between the headband end portion12a and friction washers 30 and 32, an integral rectangular projectingrib 30a is formed on the inner side of washer 30 and is arranged toproject outwardly sufficiently to extend through the slot 38 in headbandl2 and into an elongated rectangular groove 32a formed in the inner wallof washer 32. Thus, it will be appreciated that the construction andarrangement of parts are such that no relative rotation between thewashers 30 and 32 or between these washers and the slotted end portionsof the headband can occur. On the other hand, when the adjustment of thenut 34 against the outer side of spring washer 40 is proper, thefrictional engagement between washers 30, 32 and the slotted headbandwill allow sliding adjustment therebetween when the washers are grippedby one hand and the headband is pressed lengthwise by the other.

Even though the two studs 22 at opposite sides of the headset arerequired to move with the headband when it is swung from one of itsordinary positions of use to another, nevertheless, such swinging actionof the headband is permitted by he rotational action of the ball-headedends 220 of the studs embedded within their respective sockets 25.

For example, it may be the wish of a person servicing a jet aircraft towear his headset for sound-attenuation purposes with the headbandextending over the head, and thereafter he may wish to swing theheadband into a position lying closely adjacent the nape of his neck,such as when a cap or protective helmet is also to be used, or he maywish to swing the headband to a position under his chin and such uses ofthe device, while in service may be readily and smoothly accomplished bymerely exerting a firm pressure upon the headband.

In FIGS. 5 and 6, a somewhat modified form of the invention is shown. Inthese Figures at 121 is indicated a headband which has only one of itsopposite end portions shown at end Each nd portion, it will beunderstood, is stamped or otherwise formed so as to be more or less of aspoon-shaped formation with the concave side thereof facing inwardly. Itwill be appreciated that a ball-headed stud 122, (like stud 22 in FIGS.1-4) has its spherically-shaped inner end 122a embedded, during theearcup molding operation, in the plastic wall of the earcup 14 and so asto have limited universal swivelling motion as mentioned before, but, onthe otherhand, hasits stem portion 122b slightly modified. This stemportion 122b, as shown, is straightsided and may be arranged, forexample, to extend into a centered hole in the spoon-shaped centralportion of the end and there securely rigidly connected to the centralportion as by welding, riveting, peening or the like for effecting afirm mechanical connection. Thus, the ends of the headband will more orless hood-in the connecting means for the earcups. However, the sameuniversal swivelling and pivotal motion of the earcups will be provided.When such permanent connections are used at the opposite end of theflexible headband, it will be preferable to employ in known manner anadjustable extensible arrangement for the headband intermediate theopposite ends. In such case, the headband would preferably have twosemi-circular halves slidably related to each other and held together bya polyvinyl chloride channel, in known manner. Thus, the length of theheadband may be changed readily as required.

Advantages afforded by this modified construction are that it is of lessweight upon the wearers head and also that it may be constructed in amore economical fashion; nevertheless, each earcup may be swivelled orrotated into any one of its many different positions of adjustments andthe headband may be easily and readily pivoted about the two ball-headedend portions of the studs embedded within the earcups into any positiondesired by the wearer merely by pressing on the headband. The smoothfirm frictional engagement provided by the ball-headed studs within theearcup cavities will still be present and provide a firm gripping actionsufficient to ordinarily retain the headband in any given operationposition.

An important consideration of the present invention is the fact that theearcups are formed of any one of a number of well-known rigidthermoplastic or thermosetting materials by an injection molding processwhich embeds the spherically shaped end of the supporting studs 22within the plastic material but, nevertheless, provides a firm grippingaction of the ball portion thereof while also allowing desired dampenedpivotal, universal swivelling and rotational movements therebetween.Furthermore, the amount of resistance to such motion may be easily andaccurately controlled. Also, the construction is such that the joints soformed in the plastic material are self-lubricating and will remainsubstantially free from any penetration of dirt, dust or the like.

Each earcup is formed between complementary pairs of molds membersrecessed to provide a mold cavity within which is placed before the moldparts are closed the mounting stud 22 in such a manner that the greaterpart of the ball-headed portion thereof will become permanently embeddedin the plastic material while, nevertheless, having the stem portionthereof remain free of the plastic and thus free to move relativethereto the desired or in any direction from its centered position.

In FIG. 7, two mold halves 131 and 133 are shown in engaging positionready to receive the plastic material for forming a molded earcup. Itwill be seen that the mold half 131 is provided with a finished formedsurface 131a of predetermined desired size and shape and the mold half133 is provided with finished mold surface 133a of a differentpredetermined complementary size and shape. These surfaces are suitablyrelated so as to effect therebetween a mold cavity 135 of properproportions for forming earcups like that shown at 14 in FIG. 1. Arecessed portion 136 extends about the edge of the mold half 133 in sucha way as to form a small peripheral retaining flange upon the finishedearcup for aiding in engagement with the ear cushion 16 when same islater in place upon the earcup. A gate and passageway for the injectionof the plastic are shown at 145.

Centrally of the mold half 133 is provided a tubular insert 137 whichhas a recessed upper surface 138 suitably shaped and arranged forforming the thickened central portion 24 on the outer wall 14a of themolded earcup (see FIG. 3) with the ball-headed end of the stud embeddedtherein. The tubular insert 137 is provided with a central bore 141 forreceiving the stem portion of a stud each time an earcup is to be formedand before the mold members are closed for injection purposes. Theball-headed part 22a, at this time, rests upon a small upstanding collar143 formed on the tubular insert so that the greater part of theball-headed portion will be exposed within the mold cavity 135. Theresult is that the recess 27, indicated in FIG. 3, will be formed aboutthe stem portion 22b for allowing the universal pivotal action of thestud mentioned above.

The size and thickness of the central part 24 of the earcup is such asto conveniently accommodate the enlarged polished ball-headed endportion 220 of the stud 22 (or 122a of stud 122) as the case may be.Flowable plastic material may be injected into the mold cavity in knownmanner though conduit means not shown and at such time air will beallowed to escape through ports or ducts in the mold part, likewise notshown.

The results are that during injection of the plastic material into thecavity, this material flows partially about the ball portion 22a of thestud 22 while forming the thicker part 24 and that when the mold halvesare later opened and the rigidly formed earcup removed therefrom, thestud partially embedded within the plastic material will remain in theearcup when same is removed from the mold cavity. However, normalcooling and solidifying of the plastic material will cause the materialto contract more firmly about the enlarged ball-shaped end portion ofthe stud and will provide a firm gripping action thereof. In fact,curing of the plastic over the next several weeks has also been found toincrease slightly this firm gripping action.

The mold cavity surfaces are so shaped as to provide easy separation ofthe halves and easy removal of the cup as well as the stud 22.

Depending upon the size of the earcup and the amount of resistancedesired with reference to its swivelling action and rotation, it is aneasy matter in such an earcup and headband construction to control theamount of friction to be provided the ball-headed stud and the plasticof the cavity and this may be done merely by a change in diameter sizeof the ball being used.

Thus, if the weight of the earcups to be molded is increased, forexample, in a particular model wherein greater sound attenuation is tobe provided in comparison with the weight of a different lighter-weightmodel or is made heavier due to earphone being carried within theearcups, the frictional dampening resistance to swivelling action may beincreased and easily controlled in amount by a change in the diameter ofthe ball-headed end of the stud to be used.

A small increase in the diameter of the ball-headed end will provide arelatively large increase in the amount of sliding areas being grippedand a large in crease in the frictional resistance provided theconstruction. The total frictional areas involved in any instance wouldbe substantially equal to 4-rrr and thus doubling the diameter of theball, for example, would result in at least a four-fold increase intorque required to rotate the stud.

Several different commercially available plastic materials which may besatisfactorily employed for forming rigid earcups are mentioned belowand each is followed by a first column of numbers which represent rangesof coefficients of friction for these materials used in combination withpolished stainless steel and a second column of numbers which representranges for the shrinkage factors for these materials.

Approx. per lineal inch Nylon 0.15 0.0090.015 Nylon (impregnated 0.20..001 0.005 with fiber glass) Delrin (Acetal Resin) 0.15 0.025 0.030Teflon 0.04 0.003 0.060 Polyethylene 0.21 0.020 0.050 A.B.S.(acrylonytrile 0.15-0.25 0.003 0.008

Obviously, various combinations of coefficients of friction and ofshrinkage factors will result in a wide range of available resistancesto the rotation of the ballheaded stud. Thus, at least three differentparameters are available to the designer:

1. Ball diameter 2. Coefficient of friction 3. Shrinkage factor for aconstant molding cycle. While all of these plastics are veryserviceable, the last mentioned may be preferred because it is lessexpensive to manufacture.

Laboratory tests of an earcup initially having a 12 ounce resistance topivotal action of the stud embedded therein have provided, for example,after 250 revolutions of the stud in an orbital path at the rate ofrevolutions per minute an increase in resistance to 16 ounces and,furthermore, this increased resistance has remained substantiallyunchanged after 500, 750, and 1000 intermittent revolutions of suchstud.

Having described my invention, 1 claim:

1. A headset comprising a flexible headband having opposite endportions, a pair of sound-attenuating earcups carried by said headbandadjacent said opposite end portions thereof, each earcup being formed ofrigid molded plastic material and having a solid outer wall peripherallyintegrally connected to an endless surrounding solid side wall, eachside wall in turn carrying upon all parts of its endless inner edge acentrally apertured flexible head-engaging cushion so as to define withits earcup an enclosed sound-attenuating air space when each earcup ispositioned against the wearer's head, and connecting means securing eachof said earcups to said headband opposite end portions, each connectingmeans comprising a metallic stud secured to one of said headband endportions and having a smooth enlarged spherically-shaped inner end, asocket formed in the solid outer plastic wall portion of the earcupadjacent thereto, the major portion of said enlarged inner end beingpermanently embedded within said socket the rigid plastic materialforming said socket providing a firm gripping action upon saidspherically-shaped inner end which is such as to normally preventrelative movement between said earcup and said stud while allowingsmooth relative movement therebetween when either is subjected to asmall external force, said opposite end portions having elongated slots,each said stud of said connecting means extending through one of saidslots, respectively, and a pair of friction washers providing a grippingaction against the opposite sides of each of said end portions, one ofsaid washers of each pair being secured to said stud so as to preventrotation therebetween, said stud extending through said pair of washers,one washer of said pair of washers having a projecting rib and the otherwasher having a complementary recess therein, said rib extending throughsaid slot into said complementary recess in the other washer of saidpair of washers for preventing relative movement between said washersand said headband.

2.'The combination defined in claim 1 wherein an annular recess isformed in the plastic of said earcup around said stud adjacent thespherically-shaped inner end thereof, said recess being of such size asto allow universal swivelling action of said earcup about saidspherically-shaped inner end a limited angular amount in any desireddirection from its normal centered position.

1. A headset comprising a flexible headband having opposite endportions, a pair of sound-attenuating earcups carried by said headbandadjacent said opposite end portions thereof, each earcup being formed ofrigid molded plastic material and having a solid outer wall peripherallyintegrally connected to an endless surrounding solid side wall, eachside wall in turn carrying upon all parts of its endless inner edge acentrally apertured flexible head-engaging cushion so as to define withits earcup an enclosed sound-attenuating air space when each earcup ispositioned against the wearer''s head, and connecting means securingeach of said earcups to said headband opposite end portions, eachconnecting means comprising a metallic stud secured to one of saidheadband end portions and having a smooth enlarged spherically-shapedinner end, a socket formed in the solid outer plastic wall portion ofthe earcup adjacent thereto, the major portion of said enlarged innerend being permanently embedded within said socket the rigid plasticmaterial forming said socket providing a firm gripping action upon saidspherically-shaped inner end which is such as to normally preventrelative movement between said earcup and said stud while allowingsmooth relative movement therebetween when either is subjected to asmall external force, said opposite end portions having elongated slots,each said stud of said connecting means extending through one of saidslots, respectively, and a pair of friction washers providing a grippingaction against the opposite sides of each of said end portions, one ofsaId washers of each pair being secured to said stud so as to preventrotation therebetween, said stud extending through said pair of washers,one washer of said pair of washers having a projecting rib and the otherwasher having a complementary recess therein, said rib extending throughsaid slot into said complementary recess in the other washer of saidpair of washers for preventing relative movement between said washersand said headband.
 1. A headset comprising a flexible headband havingopposite end portions, a pair of sound-attenuating earcups carried bysaid headband adjacent said opposite end portions thereof, each earcupbeing formed of rigid molded plastic material and having a solid outerwall peripherally integrally connected to an endless surrounding solidside wall, each side wall in turn carrying upon all parts of its endlessinner edge a centrally apertured flexible head-engaging cushion so as todefine with its earcup an enclosed sound-attenuating air space when eachearcup is positioned against the wearer''s head, and connecting meanssecuring each of said earcups to said headband opposite end portions,each connecting means comprising a metallic stud secured to one of saidheadband end portions and having a smooth enlarged spherically-shapedinner end, a socket formed in the solid outer plastic wall portion ofthe earcup adjacent thereto, the major portion of said enlarged innerend being permanently embedded within said socket the rigid plasticmaterial forming said socket providing a firm gripping action upon saidspherically-shaped inner end which is such as to normally preventrelative movement between said earcup and said stud while allowingsmooth relative movement therebetween when either is subjected to asmall external force, said opposite end portions having elongated slots,each said stud of said connecting means extending through one of saidslots, respectively, and a pair of friction washers providing a grippingaction against the opposite sides of each of said end portions, one ofsaId washers of each pair being secured to said stud so as to preventrotation therebetween, said stud extending through said pair of washers,one washer of said pair of washers having a projecting rib and the otherwasher having a complementary recess therein, said rib extending throughsaid slot into said complementary recess in the other washer of saidpair of washers for preventing relative movement between said washersand said headband.